OTL-200 is a cryopreserved dispersion for infusion containing autologous CD34+ cell enriched population that contains haematopoietic stem and progenitor cells (HSPC) transduced ex vivo using a lentiviral vector encoding the human arylsulfatase A (ARSA) gene. MLD is an autosomal recessive lysosomal storage disorder (LSD) characterized by severe and progressive demyelination affecting the central and peripheral nervous system. The aim of this clinical study is to assess the pharmacodynamic effect and long-term clinical efficacy and safety of OTL-200 in Late Juvenile MLD patients.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
TREATMENT
Masking
NONE
Enrollment
6
All subjects will receive OTL-200 gene therapy and will be followed up for 8 years following treatment with OTL-200.
Ospedale San Raffaele - Telethon Institute for Gene Therapy (OSR-TIGET)
Milan, Italy
Evaluation of OTL-200 Arylsulfatase A (ARSA) activity levels in Cerebrospinal Fluid (CSF)
Change from baseline in ARSA activity levels in CSF
Time frame: 24 months after treatment
Evaluation of OTL-200 on the neuronal metabolite ratio of N-acetyl-aspartate (NAA) to creatine (Cr) in white matter regions of the brain
Change from baseline in neuronal metabolite ratio of N-acetyl-aspartate (NAA) to creatine (Cr) in white matter regions of interest of the brain
Time frame: 24 months after treatment
Change in ARSA activity levels in CSF from baseline
Measured to assess the pharmacodynamic activity of OTL-200 in the Central Nervous System (CNS) post-treatment
Time frame: multiple visits up to 8 years post gene-therapy
Change from baseline in neuronal metabolite ratio of NAA: Cr in white matter regions of interest of the brain
Measured to assess the pharmacodynamic activity of OTL-200 in neuronal metabolite ratio of NAA to Cr in white matter regions of interest of the brain post-treatment
Time frame: multiple visits up to 8 years post gene-therapy
Change from baseline in ARSA levels in total peripheral blood mononuclear cells (PBMCs)
Measured to assess the pharmacodynamic activity of OTL-200 in circulating total PBMCs post-treatment
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Change from baseline in ARSA levels in PB CD14+
Measured to assess the pharmacodynamic activity of OTL-200 in circulating CD14+ post-treatment
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Change from baseline in ARSA levels in PB CD15+
Measured to assess the pharmacodynamic activity of OTL-200 in circulating CD15+ post-treatment
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Neuronal metabolite ratios as compared to baseline, siblings and/or untreated historical controls (may include but not limited to Cho:Cr, mIns:Cr, Lac: Cr, Cho: NAA, NAA: H2O, Cho: H2O, mIns: H2O, Lac: H2O) in white matter regions of interest
Measured to assess the pharmacodynamic activity of OTL-200 in neuronal metabolite ratios in white matter regions of interest of the brain post-treatment compared to siblings and/or untreated historical controls
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Engraftment as measured by percent lentiviral positive (%LV+) in bone marrow (BM) progenitors
Engraftment of transduced cells will be determined by measuring the percentage of hematopoietic colony-forming cells harboring the integrated vector by quantitative polymerase chain reaction (qPCR).
Time frame: At D30 and multiple visits up to 8 years post gene-therapy
Vector copy number (VCN) in BM mononuclear cells
Engraftment of transduced cells will be determined by measuring the VCN per genome in BM-derived cells.
Time frame: At D30 and multiple visits up to 8 years post gene-therapy
VCN in Peripheral blood PBMCs
Engraftment of transduced cells will be determined by measuring the VCN per genome in PBMCs.
Time frame: At D60 and multiple visits up to 8 years post gene-therapy
Change in severity scale for brain magnetic resonance imaging (MRI)
Brain MRI will be assessed using modified Loes Score and demyelination load on T1w, T2w and FLAIR imaging.
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Change in neurocognitive function
Neurocognitive assessments will use Bayley Scale of Infant and Toddler Development (BSID), Wechsler Preschool and Primary Scale of Intelligence (WPPSI), Wechsler Intelligence Scale for Children (WISC), or Wechsler Adult Intelligence Scale (WAIS) according to the age of the participant to encompass performance, verbal, full scale IQ measures, processing speed and working memory indices
Time frame: 24 months and multiple visits up to 8 years post gene-therapy as compared to baseline
Change in full neurological clinical examination (NCE)
Neurological examinations will be performed to evaluate the effect of OTL-200 on the onset or progression of MLD disease.
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Change in Gross Motor Function Classification (GMFC)-MLD
GMFC-MLD will evaluate the change in motor function according to seven clinically relevant levels of walking, sitting, locomotion, trunk and head control. The scoring range is from 0 (walking without support with quality of performance normal for age) to 6 (loss of any locomotion as well as loss of any head and trunk control).
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Change in NCV
NCV will be assessed by electroneurography which is a technique used to test and quantify the nerve conduction and impulse propagation along motor and sensory peripheral nerves.
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Vineland Adaptive Behavior Scale (VABS)
VABS will assess the individual's ability to undertake daily activities appropriate for their age group.
Time frame: 24 months and multiple visits up to 8 years post gene-therapy
Conditioning regimen related toxicity and AEs
To evaluate the safety and tolerability of the HSPC GT procedure.
Time frame: up to 8 years post gene-therapy
Non-conditioning related AEs
To evaluate the safety and tolerability of OTL-200.
Time frame: up to 8 years post gene-therapy
Hematological reconstitution
Hematological reconstitution defined as absolute neutrophil count \[ANC\] ≥ 500/µL and platelet count ≥20,000 platelets/μL with associated evidence of BM recovery
Time frame: By Day 60 post-gene therapy
Incidence of infusion related reactions
To evaluate the safety and tolerability of the HSPC GT procedure.
Time frame: up to 8 years post gene-therapy
Immune response (e.g. anti-ARSA antibodies)
Plasma samples will be collected for anti-ARSA antibody analysis
Time frame: up to 8 years post gene-therapy
Abnormal Clonal Proliferation (ACP)
Malignancy or ACP due to insertional oncogenesis will be evaluated using different tests and procedures.
Time frame: up to 8 years post gene-therapy
Replication Competent Lentivirus (RCL
Molecular monitoring of RCL will be assessed via enzyme-linked immunosorbent assay (ELISA) test for serum human immunodeficiency virus (HIV) p24 antigen. A positive HIV p24 test result is subject to second level testing including: a) DNA PCR for vesicular stomatitis virus G (VSV-G) envelope (PBMC), and b) reverse transcription (RT)-PCR for serum HIV-pol ribonucleic acid (RNA) (plasma).
Time frame: baseline, 1, 3, 6, and 12 months, then once a year up to 8 years post gene-therapy
Integration Site analysis findings
Detailed analysis of LV integrations will be performed on PB and BM cells, to monitor the nature and distribution of Integration Sites
Time frame: 6, 12 months, then once a year up to 8 years post gene-therapy
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